`data_filter`

Filter array items by a condition.

Parameters

source_keystringrequired: Context key holding the source array
output_keystringrequired: Context key where the filtered array will be stored
fieldstringrequired: Field name to evaluate on each array item
opstringrequired: Comparison operator (see table below)
valueany: Value to compare against. Required for all operators except exists and not_exists.

Operators

Operator	Description	Value type
`eq`	Equal (`==`)	any
`neq`	Not equal (`!=`)	any
`gt`	Greater than (`>`)	number
`lt`	Less than (`<`)	number
`gte`	Greater than or equal (`>=`)	number
`lte`	Less than or equal (`<=`)	number
`contains`	String contains substring	string
`exists`	Field exists and is not null	— (value ignored)
`not_exists`	Field is missing or null	— (value ignored)

Numeric operators (gt, lt, gte, lte) compare values as 64-bit floats. If either side is not a number, the item is excluded. The contains operator performs a string substring check; if either side is not a string, the item is excluded.

Context Output

{output_key} — the filtered array
{output_key}_count — number of items in the filtered array

Example

flow:step("filter_active", nodes.data_filter({
    source_key = "users",
    field = "status",
    op = "eq",
    value = "active",
    output_key = "active_users"
}))

flow:step("filter_high_value", nodes.data_filter({
    source_key = "orders",
    field = "total",
    op = "gte",
    value = 100,
    output_key = "high_value_orders"
})):depends_on("fetch_orders")

flow:step("filter_has_email", nodes.data_filter({
    source_key = "contacts",
    field = "email",
    op = "exists",
    output_key = "with_email"
}))